docs: def user(self, username=None):
          """A user resource that represents a registered user in the portal."""
          if username is None:
              username = self.__getUsername()
          parsedUsername = urlparse.quote(username)
          url = self.root + "/%s" % parsedUsername
          return User(url=url,
                      securityHandler=self._securityHandler,
                      proxy_url=self._proxy_url,
                      proxy_port=self._proxy_port,
                      initialize=False)